Quantum Mechanics of Atoms

The Wave Function and Its Interpolation

In quantum mechanics the amplitude of a particle wave is called the wave function and is given the symbol

If we are dealing only with one photon:

At any point the square of the electric field strength is a measure of the probability that a photon will be at that location.

For a single particle:

2 at a certain point in space and time represents the probability of finding the electron at the given position and time.

Important: there is no way to predict where one electron would hit the screen.

We could predict only probabilities.

The main point of this discussion is this: if we treat electrons as if they were waves, then represents the wave amplitude. If we treat them as particles, then we must treat them on probabilistic basis.

The Heisenberg Uncertainty Principle

The act of observing produces a significant uncertainty in either the position or the momentum of electron.

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Position uncertainty of a baseball

What is the uncertainty in position, imposed by the uncertainty principle, of a 150-g baseball thrown at 42+-1 m/s? Should the umpire be concerned? Can he use Heisenberg as an excuse?